File corruption.

[Niprop]

Firstly, this is why you would have mini CD cases. =P

Could you elaborate on how DPPt/HGSS would delete all your progress before the save completed? I'm curious as to how the game mechanics would work.

Okay, say that when your DS is shut off, that the file was in the middle of saving, lets say a Pokémon's ID. When the DS is turned off, the DS didn't have enough time to save it completely, giving it a large chance of forming incomplete, or invalid data. I'm not sure how it works exactly, but a Check-Sum of sorts must track such things so in the case that the DS were to shut off in between the point of Saving and the point of the message "Save complete." The Check-Sum quickly discards the corrupted data (the entire file, just to be safe), and instead starts up the previous save before the corrupted save, which is stored in its own seperate blocks for in the case a corruption were to happen. At least, that's how I remember it. Don't quote me on this.

 

[Teh Blazer]

GBC for sure. The only save file I lost was on my Silver. And I put so much effort into it...

 

[Enigma]

1st gen. games tend to die the most. I had a Sliver game that died (it was my favorite), then I got another Sliver. Guess what? That Sliver died too. >_<